Human echolocation is the ability of a person to sense objects in his or her surroundings by generating a sound wave and then detecting echoes off of those objects. This ability can be used by an unsighted person to maneuver within his or her environment. The sound waves can be generated, for example, by making a clicking noise with the mouth or by tapping a cane. This phenomenon is similar in principle to active sonar used by submarines or to echolocation used by certain species of animals, such as dolphins or bats.
By interpreting the sounds reflecting off nearby objects, a person trained in human echolocation can determine the approximate location, dimensions, and depth of objects and use this information to navigate his or her environment. In one widely publicized example reported by CBS television news and People magazine, an unsighted teenage boy used echolocation to steer around objects while walking, roller skating, and participating in other normal daily activities.
A drawback to human echolocation is that the generated sounds are of a comparatively low frequency and rate. Consequently the surroundings cannot be evaluated with the same detail as echolocating animals such as dolphins and bats, which use a higher frequency. Further, the generated sounds are not always of the same amplitude or frequency, and the echoes bouncing off nearby objects are thus more difficult to interpret. In addition, the tapping and clicking noises can be obtrusive to sighted persons in the vicinity.
Thus there is a need for an improved human echolocation system.